In general, in an image forming apparatus such as a laser printer, a laser beam emitted from an optical unit is irradiated to a photosensitive drum so as to form an electrostatic latent image on a surface of the photosensitive drum, and toner is supplied to the electrostatic latent image so formed from a development unit. Then, a sheet is conveyed to pass between the photosensitive drum with a toner image formed thereon and a transfer roller to transfer the toner image to the sheet, and the toner image so transferred is heat fixed on the sheet by a fixing unit.
JP-A-2005-215229 discloses an image forming apparatus which can perform double-sided printing. In the image forming apparatus, when the double-sided printing is performed, a discharge roller for conveying the sheet discharged from the fixing unit to the outside of the apparatus is reversed to convey the sheet to a returning path. Then, the sheet is conveyed to pass again between the photosensitive drum and the transfer roller to transfer a toner image to the sheet, and the sheet is discharged to the outside of the apparatus after the toner image so transferred has been fixed on the sheet by the fixing unit.
Incidentally, in the image forming apparatus which can perform double-sided printing, the returning path is independently provided between the transfer roller provided on the main body of the apparatus and a sheet feeding tray provided in a lower portion of the apparatus. Therefore, when the returning path is jammed with a recording sheet, the jammed sheet is not easily removed from the returning path.